Length
Convert micrometre (µm) to thousandth of an inch (mil). Length units span pipe diameters (mm, inch), plant dimensions (m, ft), and roughness (µm) — mixing metric and imperial is routine.
1 µm = 0.03937008 mil
To convert micrometre to thousandth of an inch, multiply the µm value by 0.03937008. To go the other way, divide by 0.03937008 (or multiply by 25.4).
| µm | mil |
|---|---|
| 1 | 0.03937008 |
| 2 | 0.07874016 |
| 5 | 0.1968504 |
| 10 | 0.3937008 |
| 25 | 0.984252 |
| 50 | 1.968504 |
| 100 | 3.937008 |
| 250 | 9.84252 |
| 500 | 19.68504 |
| 1000 | 39.37008 |
Pipe sizes are labelled in inches (NPS) but calculated in mm; equipment layouts mix metres and feet.
Velocity scales with the inverse square of diameter, so a small length error compounds quickly in flow calculations.
Worked example. A length of 100000 µm is 3937.008 mil.
Multiply the value in µm by 0.03937008 to get mil. For example, 10 µm = 0.3937008 mil.
1 µm equals 0.03937008 mil.
Pipe sizes are labelled in inches (NPS) but calculated in mm; equipment layouts mix metres and feet.